Hi,
maybe you could use something like:
t = Time.now.to_i
use_random_seed t
puts rand
which uses a timestamp to change the random_seed constantly. But - as @samaaron told on different occasions - using native ruby stuff is a bit like the Wild West. You should not be sure whether and how long the laws of Sonic Pi will accept and support that. But the code bit above seems to work. Someone with more internal knowledge might have a better idea.